Note 2 - Revenues - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2021	Dec. 31, 2020
Revenues	$ 26,011	$ 40,389	$ 46,491	$ 32,728	$ 40,322	$ 54,614	$ 54,926	$ 48,634	$ 145,619	$ 198,496
Consolidation, Eliminations [Member]
Revenues									(360)	(137)
Heavy Fabrications [Member] | Operating Segments [Member]
Revenues									101,994	155,198
Gearing [Member] | Operating Segments [Member]
Revenues									28,583	25,136
Industrial Solutions [Member] | Operating Segments [Member]
Revenues									$ 15,402	$ 18,299